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/* irq-mb93093.c: MB93093 FPGA interrupt handling
*
* Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/delay.h>
#include <asm/irq.h>
#include <asm/irc-regs.h>
#define __reg16(ADDR) (*(volatile unsigned short *)(__region_CS2 + (ADDR)))
#define __get_IMR() ({ __reg16(0x0a); })
#define __set_IMR(M) do { __reg16(0x0a) = (M); wmb(); } while(0)
#define __get_IFR() ({ __reg16(0x02); })
#define __clr_IFR(M) do { __reg16(0x02) = ~(M); wmb(); } while(0)
/*
* off-CPU FPGA PIC operations
*/
static void frv_fpga_mask(unsigned int irq)
{
uint16_t imr = __get_IMR();
imr |= 1 << (irq - IRQ_BASE_FPGA);
__set_IMR(imr);
}
static void frv_fpga_ack(unsigned int irq)
{
__clr_IFR(1 << (irq - IRQ_BASE_FPGA));
}
static void frv_fpga_mask_ack(unsigned int irq)
{
uint16_t imr = __get_IMR();
imr |= 1 << (irq - IRQ_BASE_FPGA);
__set_IMR(imr);
__clr_IFR(1 << (irq - IRQ_BASE_FPGA));
}
static void frv_fpga_unmask(unsigned int irq)
{
uint16_t imr = __get_IMR();
imr &= ~(1 << (irq - IRQ_BASE_FPGA));
__set_IMR(imr);
}
static struct irq_chip frv_fpga_pic = {
.name = "mb93093",
.ack = frv_fpga_ack,
.mask = frv_fpga_mask,
.mask_ack = frv_fpga_mask_ack,
.unmask = frv_fpga_unmask,
.end = frv_fpga_end,
};
/*
* FPGA PIC interrupt handler
*/
static irqreturn_t fpga_interrupt(int irq, void *_mask, struct pt_regs *regs)
{
uint16_t imr, mask = (unsigned long) _mask;
imr = __get_IMR();
mask = mask & ~imr & __get_IFR();
/* poll all the triggered IRQs */
while (mask) {
int irq;
asm("scan %1,gr0,%0" : "=r"(irq) : "r"(mask));
irq = 31 - irq;
mask &= ~(1 << irq);
generic_irq_handle(IRQ_BASE_FPGA + irq, regs);
}
return IRQ_HANDLED;
}
/*
* define an interrupt action for each FPGA PIC output
* - use dev_id to indicate the FPGA PIC input to output mappings
*/
static struct irqaction fpga_irq[1] = {
[0] = {
.handler = fpga_interrupt,
.flags = IRQF_DISABLED,
.mask = CPU_MASK_NONE,
.name = "fpga.0",
.dev_id = (void *) 0x0700UL,
}
};
/*
* initialise the motherboard FPGA's PIC
*/
void __init fpga_init(void)
{
int irq;
/* all PIC inputs are all set to be edge triggered */
__set_IMR(0x0700);
__clr_IFR(0x0000);
for (irq = IRQ_BASE_FPGA + 8; irq <= IRQ_BASE_FPGA + 10; irq++)
set_irq_chip_and_handler(irq, &frv_fpga_pic, handle_edge_irq);
/* the FPGA drives external IRQ input #2 on the CPU PIC */
setup_irq(IRQ_CPU_EXTERNAL2, &fpga_irq[0]);
}
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